The objectives and methods and significance of present and proposed studies of Acute Leukemia Cooperative Group B were detailed in protocols submitted with the application that led to Public Health Service Grant CA 04646. This application represents a request for continued support of studies undertaken and projected in cooperation with Acute Leukemia Group B. At present, studies involving chemotherapy of acute leukemia, multiple myeloma, malignant lymphoma, and solid tumors of children are being included in the cooperative activities of Acute Leukemia Cooperative Group B.